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Toumai ... A "new" date

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  • m3dodds
    New Date on Sahelanthropus tchadensis and Australopithecus bahrelghazali (Afarensis) http://tinyurl.com/3dz6s3 6.8 - 7.2 Ma? What s new? It was thought to be
    Message 1 of 15 , Mar 1, 2008
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      New Date on Sahelanthropus tchadensis and
      Australopithecus bahrelghazali
      (Afarensis)
      http://tinyurl.com/3dz6s3


      6.8 - 7.2 Ma?

      What's new?
      It was thought to be older than 6 Ma when first
      discovered in Chad ...

      IMO this has more to do with, getting Toumai
      accepted as a hominid ancestor ...


      "[quote] ...With its mosaic of plesiomorphic and
      apomorphic characters Sahelanthropus tchadensis,
      the earliest known hominid ..., its probably very
      close in time to this divergence contrary to the
      unlikely ''provocative explanation,'' which
      recently suggested a ''possible hybridization
      in the human-chimp lineage before finally
      separating less than 6.3 Ma'' ..."


      Would suggest ... it is they who are being ...
      provocative.



      ---m3d
    • Don
      Wow! That s a testy little exchange on that link. getting Toumai accepted as a hominid ancestor... indeed It s definitely within the reach of evolution for
      Message 2 of 15 , Mar 1, 2008
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        Wow! That's a testy little exchange on that link.

        getting Toumai accepted as a hominid ancestor... indeed

        It's definitely within the reach of evolution for an isolated group to physically morph
        without speciating and then hybridizing (or extincting) later. Eg, founders effect followed
        by an equalizing genetic drift.
        Comparing bonobo to chimp is an obvious case of a branch more like human but still not
        ancestor to human.


        --- In AAT@yahoogroups.com, "m3dodds" <dons3148@...> wrote:
        >
        >
        >
        >
        >
        > New Date on Sahelanthropus tchadensis and
        > Australopithecus bahrelghazali
        > (Afarensis)
        > http://tinyurl.com/3dz6s3
        >
        >
        > 6.8 - 7.2 Ma?
        >
        > What's new?
        > It was thought to be older than 6 Ma when first
        > discovered in Chad ...
        >
        > IMO this has more to do with, getting Toumai
        > accepted as a hominid ancestor ...
        >
        >
        > "[quote] ...With its mosaic of plesiomorphic and
        > apomorphic characters Sahelanthropus tchadensis,
        > the earliest known hominid ..., its probably very
        > close in time to this divergence contrary to the
        > unlikely ''provocative explanation,'' which
        > recently suggested a ''possible hybridization
        > in the human-chimp lineage before finally
        > separating less than 6.3 Ma'' ..."
        >
        >
        > Would suggest ... it is they who are being ...
        > provocative.
        >
        >
        >
        > ---m3d
        >
      • m3dodds
        ... It does seem to be more about the inflated ego s of PAs than anything else. ... Agree. [quote] ...The radiochronological data concerning Sahelanthropus
        Message 3 of 15 , Mar 2, 2008
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          --- In AAT@yahoogroups.com, "Don" <shux2k@...> wrote:


          >
          > Wow! That's a testy little exchange on that link.
          > getting Toumai accepted as a hominid ancestor...
          > indeed


          It does seem to be more about the inflated ego's
          of PAs than anything else.



          > It's definitely within the reach of evolution for
          > an isolated group to physically morph without
          > speciating and then hybridizing (or extincting)
          > later. Eg, founders effect followed by an
          > equalizing genetic drift.


          > Comparing bonobo to chimp is an obvious case
          > of a branch more like human but still not
          > ancestor to human.


          Agree.




          [quote] ...The radiochronological data concerning
          Sahelanthropus tchadensis (Toumai, TM 266) reported
          here is an important cornerstone both for establishing
          the earliest stages of hominid evolution and for new
          calibrations of the molecular clock. Thus, Sahelanthropus
          tchadensis testifies that the last divergence between
          chimps and humans is certainly not much more recent
          than 8 Ma, which is congruent with Chororapithecus
          abyssinicus,the new 10-Ma-old Ethiopian paleogorillid
          (39).With its mosaic of plesiomorphic and apomorphic
          characters Sahelanthropus tchadensis, the earliest
          known hominid (1, 2, 40), is probably very close in time
          to this divergence contrary to the unlikely ``pro-vocative
          explanation,'' which recently suggested a ``possible
          hybridization in the human-chimp lineage before finally
          separating less than 6.3 Ma'' (41).


          Cosmogenic nuclide dating of Sahelanthropus
          tchadensis and Australopithecus bahrelghazali:
          Mio-Pliocene hominids from Chad

          ----------------------------------------

          Don, the above is a direct quote is from their PNAS
          article that I have just downloaded this morning, I
          may be wrong but it appears to be saying that the
          chimp and human divergence could not be more recent
          8 Ma., which does not sound right...


          If you are interested in reading the article, you can
          download a pdf copy here:

          http://www.pnas.org/cgi/content/abstract/0708015105v1



          ---m3d











          In AAT@yahoogroups.com, "m3dodds" <dons3148@> wrote:

          > > New Date on Sahelanthropus tchadensis and
          > > Australopithecus bahrelghazali
          > > (Afarensis)
          > > http://tinyurl.com/3dz6s3
          > >
          > >
          > > 6.8 - 7.2 Ma?
          > >
          > > What's new?
          > > It was thought to be older than 6 Ma when first
          > > discovered in Chad ...
          > >
          > > IMO this has more to do with, getting Toumai
          > > accepted as a hominid ancestor ...
          > >
          > >
          > > "[quote] ...With its mosaic of plesiomorphic and
          > > apomorphic characters Sahelanthropus tchadensis,
          > > the earliest known hominid ..., its probably very
          > > close in time to this divergence contrary to the
          > > unlikely ''provocative explanation,'' which
          > > recently suggested a ''possible hybridization
          > > in the human-chimp lineage before finally
          > > separating less than 6.3 Ma'' ..."
          > >
          > >
          > > Would suggest ... it is they who are being ...
          > > provocative.
          > >
          > >
          > >
          > > ---m3d
          > >
          >
        • Marc Verhaegen
          ... Thanks a lot, m3d. A-E Lebatard cs.2008 PNAS 10.1073/pnas.0708015105 open access Cosmogenic nuclide dating of Sahelanthropus tchadensis and
          Message 4 of 15 , Mar 2, 2008
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            Op 02-03-2008 12:10, m3dodds <dons3148@...> schreef:

            > http://www.pnas.org/cgi/content/abstract/0708015105v1

            Thanks a lot, m3d.

            A-E Lebatard cs.2008 PNAS 10.1073/pnas.0708015105 open access
            Cosmogenic nuclide dating of Sahelanthropus tchadensis and Australopithecus
            bahrelghazali: Mio-Pliocene hominids from Chad

            Ages were determined at 2 hominid localities from the Chad Basin in the
            Djurab Desert (N-Chad):
            - Koro Toro fossiliferous area, KT 12 locality (16°00'N, 18°53'E) was the
            site of discovery of Austr.bahrelghazali (Abel) ;
            - Toros-Menalla fossiliferous area, TM 266 locality (16°15'N, 17°29'E) was
            the site of discovery of Sahelanthr.tchadensis (Toumaï).

            At both localities, the evolutive degree of the associated fossil mammal
            assemblages allowed a bio-chronological estimation of the hominid remains:
            - early Pliocene 3­3.5 Ma at KT 12 ;
            - late Miocene c.7 Ma at TM 266.

            Atmospheric 10Be (a cosmogenic nuclide) was used to quasi-continuously date
            these sedimentary units.
            - The authigenic 10Be/9Be dating of a pelite relic within the sedimentary
            level containing Abel yields an age of 3.58 ± 0.27 Ma that points to the
            contemporaneity of Abel with Lucy.
            - The 28 10Be/9Be ages obtained within the anthracotheriid unit containing
            Toumaï bracket the age to lie between 6.8 & 7.2 Ma. This chronological
            constraint is an important cornerstone
            -- for establishing the earliest stages of hominid evolution &
            -- for new calibrations of the molecular clock.

            > [quote] ...The radio-chronological data concerning
            > Sahelanthropus tchadensis (Toumai, TM 266) reported
            > here is an important cornerstone both for establishing
            > the earliest stages of hominid evolution and for new
            > calibrations of the molecular clock. Thus, Sahelanthropus
            > tchadensis testifies that the last divergence between
            > chimps and humans is certainly not much more recent
            > than 8 Ma, which is congruent with Chororapithecus
            > abyssinicus, the new 10-Ma-old Ethiopian paleo-gorillid
            > (39).

            Sigh. 14 authors who have never heard of parallel evolution & assume that
            humans descend from something halfway a gorilla & a chimp... They think
            Toumai was bipedal, hence "hominid", hence closer to H than to P.

            Toumai simply was one of the probably-many primitive hominids then (ie,
            everything in our branch after the hominid/pongid split c.15 Ma):
            Sahelanthr, Orrorin, Ouranop, Chororap, Samburup, Nakalip, Oreop.
            Both Toumai & Chorarap confirm the comparative data that early apes were
            vertical aquarborealists (hanging, climbing, floating & perhaps wading).
            Possibly they suggest the early hominids (at least in Africa) were
            remarkably large & (except, eg, for the thick enamel) gorilla-like (but this
            may be due to fossil biases).

            Good they found more exact datings, but nothing here requires any new
            "clock" calibrations or contradicts the bio-molecular findings that the H/P
            split c.5 or 4 Ma.

            --Marc

            > With its mosaic of plesiomorphic and apomorphic
            > characters Sahelanthropus tchadensis, the earliest
            > known hominid (1,2,40), is probably very close in time
            > to this divergence contrary to the unlikely "pro-vocative
            > explanation," which recently suggested a "possible
            > hybridization in the human-chimp lineage before finally
            > separating less than 6.3 Ma" (41).
          • Marc Verhaegen
            ... Fig.1+2: Both fossil seem to lay in argillaceous pelites? Abel ass.x fish cf.fig.2? What does argillaceous pelites imply? --Marc
            Message 5 of 15 , Mar 2, 2008
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              Op 02-03-2008 12:10, m3dodds <dons3148@...> schreef:

              > http://www.pnas.org/cgi/content/abstract/0708015105v1

              Fig.1+2: Both fossil seem to lay in argillaceous pelites?
              Abel ass.x fish cf.fig.2?
              What does "argillaceous pelites" imply?

              --Marc
            • m3dodds
              ... argillaceous ... (containing clay, or clay like)and pelites(sedimentary rock, made of fine particles)... ancient river beds, lake shores, estuaries?
              Message 6 of 15 , Mar 2, 2008
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                --- In AAT@yahoogroups.com, Marc Verhaegen <marc.verhaegen@...> wrote:
                >
                > Op 02-03-2008 12:10, m3dodds <dons3148@...> schreef:
                >
                > > http://www.pnas.org/cgi/content/abstract/0708015105v1
                >
                > Fig.1+2: Both fossil seem to lay in argillaceous pelites?
                > Abel ass.x fish cf.fig.2?
                > What does "argillaceous pelites" imply?
                >
                > --Marc
                >


                argillaceous ... (containing clay, or clay like)and
                pelites(sedimentary rock, made of fine particles)...
                ancient river beds, lake shores, estuaries?

                ---m3d
              • DDeden
                ... mudstone (any diatoms found?) Pelite (Greek Pelos, Clay) is a descriptive name for a clastic rock with a grain size of less than 1/16mm (originally sand or
                Message 7 of 15 , Mar 2, 2008
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                  --- In AAT@yahoogroups.com, Marc Verhaegen <marc.verhaegen@...> wrote:
                  >
                  > Op 02-03-2008 12:10, m3dodds <dons3148@...> schreef:
                  >
                  > > http://www.pnas.org/cgi/content/abstract/0708015105v1
                  >
                  > Fig.1+2: Both fossil seem to lay in argillaceous pelites?
                  > Abel ass.x fish cf.fig.2?
                  > What does "argillaceous pelites" imply?
                  >
                  > --Marc

                  mudstone (any diatoms found?)

                  Pelite (Greek Pelos, Clay) is a descriptive name for a clastic rock
                  with a grain size of less than 1/16mm (originally sand or silt)
                  Examples include slate and mudstone. The equivalent Latin-derived term
                  is Lutite. Pelite is more commonly used for a metamorphosed sediment.

                  Pilite is a rarely used name for an altered olivine that has partially
                  pseudomorphically replaced by an assemblage of
                  carbonate–chlorite–actinolite. Pilite can be identified only in a thin
                  section.

                  Pettijohn [1] gives the following descriptive terms based on grain
                  size, avoiding the use of terms such as clay or argillaceous which
                  carry an implication of chemical composition.
                • m3dodds
                  ... A clock is something that is supposed to be reasonably accurate... see: http://focus.aps.org/story/v20/st9 ... Simply walking on two legs(biped), does not
                  Message 8 of 15 , Mar 2, 2008
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                    --- In AAT@yahoogroups.com, Marc Verhaegen <marc.verhaegen@...> wrote:
                    >
                    > Op 02-03-2008 12:10, m3dodds <dons3148@...> schreef:
                    >
                    > > http://www.pnas.org/cgi/content/abstract/0708015105v1
                    >
                    >
                    > Thanks a lot, m3d.
                    >
                    > A-E Lebatard cs.2008 PNAS 10.1073/pnas.0708015105 open access
                    > Cosmogenic nuclide dating of Sahelanthropus tchadensis and
                    > Australopithecus bahrelghazali: Mio-Pliocene hominids
                    > from Chad
                    >
                    > Ages were determined at 2 hominid localities from the
                    > Chad Basin in the Djurab Desert (N-Chad):
                    > - Koro Toro fossiliferous area, KT 12 locality (16°00'N,
                    > 18°53'E) was the site of discovery of Austr.bahrelghazali
                    > (Abel) ; - Toros-Menalla fossiliferous area, TM 266
                    > locality (16°15'N, 17°29'E) was the site of discovery
                    > of Sahelanthr.tchadensis (Toumaï).
                    >
                    > At both localities, the evolutive degree of the
                    > associated fossil mammal assemblages allowed a
                    > bio-chronological estimation of the hominid remains:
                    > - early Pliocene 3­3.5 Ma at KT 12 ;
                    > - late Miocene c.7 Ma at TM 266.
                    >
                    > Atmospheric 10Be (a cosmogenic nuclide) was used to
                    > quasi-continuously date these sedimentary units.
                    > - The authigenic 10Be/9Be dating of a pelite relic
                    > within the sedimentary level containing Abel yields
                    > an age of 3.58 ± 0.27 Ma that points to the
                    > contemporaneity of Abel with Lucy.
                    > - The 28 10Be/9Be ages obtained within the anthracotheriid
                    > unit containing Toumaï bracket the age to lie between 6.8
                    > & 7.2 Ma. This chronological constraint is an important
                    > cornerstone
                    > -- for establishing the earliest stages of hominid evolution &
                    > -- for new calibrations of the molecular clock.


                    A clock is something that is supposed to
                    be reasonably accurate...

                    see:
                    http://focus.aps.org/story/v20/st9





                    > > [quote] ...The radio-chronological data concerning
                    > > Sahelanthropus tchadensis (Toumai, TM 266) reported
                    > > here is an important cornerstone both for establishing
                    > > the earliest stages of hominid evolution and for new
                    > > calibrations of the molecular clock. Thus, Sahelanthropus
                    > > tchadensis testifies that the last divergence between
                    > > chimps and humans is certainly not much more recent
                    > > than 8 Ma, which is congruent with Chororapithecus
                    > > abyssinicus, the new 10-Ma-old Ethiopian paleo-gorillid
                    > > (39).
                    >
                    > Sigh. 14 authors who have never heard of parallel
                    > evolution & assume that humans descend from something
                    > halfway a gorilla & a chimp... They think Toumai was
                    > bipedal, hence "hominid", hence closer to H than to P.


                    Simply walking on two legs(biped), does not make it
                    (or any other hominid) a direct ancestor.




                    > Toumai simply was one of the probably-many primitive
                    > hominids then (ie, everything in our branch after the
                    > hominid/pongid split c.15 Ma): Sahelanthr, Orrorin,
                    > Ouranop, Chororap, Samburup, Nakalip, Oreop.
                    > Both Toumai & Chorarap confirm the comparative data
                    > that early apes were vertical aquarborealists (hanging,
                    > climbing, floating & perhaps wading).
                    > Possibly they suggest the early hominids (at least in
                    > Africa) were remarkably large & (except, eg, for the
                    > thick enamel) gorilla-like (but this
                    > may be due to fossil biases).
                    >
                    > Good they found more exact datings, but nothing here
                    > requires any new "clock" calibrations or contradicts
                    > the bio-molecular findings that the H/P
                    > split c.5 or 4 Ma.
                    >
                    > --Marc
                    >


                    More accurate dating, but not all that much different
                    from the dates given, when first found in Chad.

                    Why the ridiculous 8 Ma, for the P/H divergence ...
                    Is it to enable Toumai dated at 7 Ma, to be counted
                    as a direct ancestor?


                    ---m3d






                    > > With its mosaic of plesiomorphic and apomorphic
                    > > characters Sahelanthropus tchadensis, the earliest
                    > > known hominid (1,2,40), is probably very close in time
                    > > to this divergence contrary to the unlikely "pro-vocative
                    > > explanation," which recently suggested a "possible
                    > > hybridization in the human-chimp lineage before finally
                    > > separating less than 6.3 Ma" (41).
                    >
                  • Marc Verhaegen
                    ... The word clock is not exact, but we know what it means. Like AAT . ... Yes, but we don t even know whether Sahelanthr walked on 2 legs on dry ground.
                    Message 9 of 15 , Mar 2, 2008
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                      Op 02-03-2008 15:13, m3dodds <dons3148@...> schreef:

                      >>> http://www.pnas.org/cgi/content/abstract/0708015105v1

                      >> A-E Lebatard cs.2008 PNAS 10.1073/pnas.0708015105 open access
                      >> Cosmogenic nuclide dating of Sahelanthropus tchadensis and
                      >> Australopithecus bahrelghazali: Mio-Pliocene hominids
                      >> from Chad
                      >> Ages were determined at 2 hominid localities from the
                      >> Chad Basin in the Djurab Desert (N-Chad):
                      >> - Koro Toro fossiliferous area, KT 12 locality (16°00'N,
                      >> 18°53'E) was the site of Austr.bahrelghazali (Abel) ;
                      >> - Toros-Menalla fossiliferous area, TM 266
                      >> locality (16°15'N, 17°29'E) was the site of discovery
                      >> of Sahelanthr.tchadensis (Toumaï).
                      >> At both localities, the evolutive degree of the
                      >> associated fossil mammal assemblages allowed a
                      >> bio-chronological estimation of the hominid remains:
                      >> - early Pliocene 3­3.5 Ma at KT 12 ;
                      >> - late Miocene c.7 Ma at TM 266.
                      >> Atmospheric 10Be (a cosmogenic nuclide) was used to
                      >> quasi-continuously date these sedimentary units.
                      >> - The authigenic 10Be/9Be dating of a pelite relic
                      >> within the sedimentary level containing Abel yields
                      >> an age of 3.58 ± 0.27 Ma that points to the
                      >> contemporaneity of Abel with Lucy.
                      >> - The 28 10Be/9Be ages obtained within the anthracotheriid
                      >> unit containing Toumaï bracket the age to lie between 6.8
                      >> & 7.2 Ma. This chronological constraint is an important
                      >> cornerstone
                      >> -- for establishing the earliest stages of hominid evolution &
                      >> -- for new calibrations of the molecular clock.

                      > A clock is something that is supposed to
                      > be reasonably accurate...
                      > http://focus.aps.org/story/v20/st9

                      The word "clock" is not exact, but we know what it means. Like "AAT".

                      >>> [quote] ...The radio-chronological data concerning
                      >>> Sahelanthropus tchadensis (Toumai, TM 266) reported
                      >>> here is an important cornerstone both for establishing
                      >>> the earliest stages of hominid evolution and for new
                      >>> calibrations of the molecular clock. Thus, Sahelanthropus
                      >>> tchadensis testifies that the last divergence between
                      >>> chimps and humans is certainly not much more recent
                      >>> than 8 Ma, which is congruent with Chororapithecus
                      >>> abyssinicus, the new 10-Ma-old Ethiopian paleo-gorillid
                      >>> (39).

                      >> Sigh. 14 authors who have never heard of parallel
                      >> evolution & assume that humans descend from something
                      >> halfway a gorilla & a chimp... They think Toumai was
                      >> bipedal, hence "hominid", hence closer to H than to P.

                      > Simply walking on two legs(biped), does not make it
                      > (or any other hominid) a direct ancestor.

                      Yes, but we don't even know whether Sahelanthr walked on 2 legs on dry
                      ground. What we know : it had vertical ancestors (Moroto vertebra) &
                      probably its for.magnum was +-underneath the skull (like tarsiers etc.),
                      IOW, it was probably also vertical (branch-hanging & floating, possibly
                      wading).

                      >> Toumai simply was one of the probably-many primitive
                      >> hominids then (ie, everything in our branch after the
                      >> hominid/pongid split c.15 Ma): Sahelanthr, Orrorin,
                      >> Ouranop, Chororap, Samburup, Nakalip, Oreop.
                      >> Both Toumai & Chorarap confirm the comparative data
                      >> that early apes were vertical aquarborealists (hanging,
                      >> climbing, floating & perhaps wading).
                      >> Possibly they suggest the early hominids (at least in
                      >> Africa) were remarkably large & (except, eg, for the
                      >> thick enamel) gorilla-like (but this
                      >> may be due to fossil biases).
                      >> Good they found more exact datings, but nothing here
                      >> requires any new "clock" calibrations or contradicts
                      >> the bio-molecular findings that the H/P
                      >> split c.5 or 4 Ma. --Marc

                      > More accurate dating, but not all that much different
                      > from the dates given, when first found in Chad.
                      > Why the ridiculous 8 Ma, for the P/H divergence ...
                      > Is it to enable Toumai dated at 7 Ma, to be counted
                      > as a direct ancestor? ---m3d

                      Every fossil-hunter wants "his" fossil to be our ancestor...
                      If Toumai 7 Ma was our ancestor, the H/P split had to be earlier...

                      --Marc
                    • Marc Verhaegen
                      ... Thanks, yes, but I d like to see more specific correlations. Sahelanthr in Anthracotheriid Unit. Remakable this association of hominid fossils with
                      Message 10 of 15 , Mar 2, 2008
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                        Op 02-03-2008 14:18, m3dodds <dons3148@...> schreef:

                        >>> http://www.pnas.org/cgi/content/abstract/0708015105v1

                        >> Fig.1+2: Both fossil seem to lay in argillaceous pelites?
                        >> Abel ass.x fish cf.fig.2?
                        >> What does "argillaceous pelites" imply? --Marc

                        > argillaceous ... (containing clay, or clay like) and
                        > pelites (sedimentary rock, made of fine particles)...
                        > ancient river beds, lake shores, estuaries? ---m3d

                        Thanks, yes, but I'd like to see more specific correlations.
                        Sahelanthr in Anthracotheriid Unit.
                        Remakable this association of hominid fossils with hippopotamid ones.

                        --Marc
                      • Marc Verhaegen
                        ... Yes, but not very near to the hominid fossils (Abel) here. Lakeside, but that s where fossilisation often occurs. Abel (fish) seems to be about as wet as
                        Message 11 of 15 , Mar 2, 2008
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                          Op 02-03-2008 15:00, DDeden <alas_my_loves@...> schreef:

                          >>> http://www.pnas.org/cgi/content/abstract/0708015105v1

                          >> Fig.1+2: Both fossil seem to lay in argillaceous pelites?
                          >> Abel ass.x fish cf.fig.2?
                          >> What does "argillaceous pelites" imply? --Marc

                          > mudstone (any diatoms found?)

                          Yes, but not very near to the hominid fossils (Abel) here.
                          Lakeside, but that's where fossilisation often occurs.
                          Abel (fish) seems to be about as "wet" as Toumai (anthrocothere).

                          > Pelite (Greek Pelos, Clay) is a descriptive name for a clastic rock
                          > with a grain size of less than 1/16 mm (originally sand or silt)
                          > Examples include slate and mudstone. The equivalent Latin-derived term
                          > is Lutite. Pelite is more commonly used for a metamorphosed sediment.
                          > Pilite is a rarely used name for an altered olivine that has partially
                          > pseudomorphically replaced by an assemblage of
                          > carbonate–chlorite–actinolite. Pilite can be identified only in a thin
                          > section.
                          > Pettijohn [1] gives the following descriptive terms based on grain
                          > size, avoiding the use of terms such as clay or argillaceous which
                          > carry an implication of chemical composition.

                          Thanks, DD.

                          --Marc
                        • m3dodds
                          ... You may find this 2002 article(in Nature) of some interest ... as it gives some idea of the location in Chad where Toumai was found(including fauna and
                          Message 12 of 15 , Mar 2, 2008
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                            --- In AAT@yahoogroups.com, Marc Verhaegen <m_verhaegen@...> wrote:
                            >
                            > Op 02-03-2008 14:18, m3dodds <dons3148@...> schreef:
                            >
                            > >>> http://www.pnas.org/cgi/content/abstract/0708015105v1
                            >
                            > >> Fig.1+2: Both fossil seem to lay in argillaceous pelites?
                            > >> Abel ass.x fish cf.fig.2?
                            > >> What does "argillaceous pelites" imply? --Marc
                            >
                            > > argillaceous ... (containing clay, or clay like) and
                            > > pelites (sedimentary rock, made of fine particles)...
                            > > ancient river beds, lake shores, estuaries? ---m3d
                            >
                            > Thanks, yes, but I'd like to see more specific correlations.
                            > Sahelanthr in Anthracotheriid Unit.
                            > Remakable this association of hominid fossils with
                            > hippopotamid ones.
                            >
                            > --Marc


                            You may find this 2002 article(in Nature) of some
                            interest ... as it gives some idea of the location
                            in Chad where Toumai was found(including fauna and
                            flora), it also includes a map giving an idea of
                            the previous extent(sizes) of Lake Chad.

                            It all seems to indicate that Toumai an its
                            kin 7 Ma, lived close to Lake(inland sea?)
                            Chad, if not on the lake shore.



                            Abstract:
                            All six known specimens of the early hominid
                            Sahelanthropus tchadensis come from Toros-Menalla
                            site 266 (TM 266), a single locality in the
                            Djurab Desert, northern Chad, central Africa.
                            Here we present a preliminary analysis of the
                            palaeontological and palaeoecological context
                            of these finds. The rich fauna from TM 266
                            includes a significant aquatic component such
                            as fish, crocodiles and amphibious mammals,
                            alongside animals associated with gallery forest
                            and savannah, such as primates, rodents, elephants,
                            equids and bovids. The fauna suggests a
                            biochronological age between 6 and 7 million years.
                            Taken together with the sedimentological evidence,
                            the fauna suggests that S. tchadensis lived close
                            to a lake, but not far from a sandy desert, perhaps
                            the oldest record of desert conditions in the
                            Neogene of northern central Africa.


                            Geology and palaeontology of the Upper Miocene
                            Toros-Menalla hominid locality, Chad

                            http://tinyurl.com/2vkwlt
                            -----------------------------------


                            ---m3d
                          • Marc Verhaegen
                            ... Thanks a lot, m3d, yes, possibly an inland sea: AFAIK the anthracotheres came from the shallow seas in the Lybian Sirt basin (F.Lihoreau cs.2006 PNAS
                            Message 13 of 15 , Mar 2, 2008
                            • 0 Attachment
                              Op 02-03-2008 18:24, m3dodds <dons3148@...> schreef:

                              >>>>> http://www.pnas.org/cgi/content/abstract/0708015105v1

                              >>>> Fig.1+2: Both fossil seem to lay in argillaceous pelites?
                              >>>> Abel ass.x fish cf.fig.2?
                              >>>> What does "argillaceous pelites" imply? --Marc

                              >>> argillaceous ... (containing clay, or clay like) and
                              >>> pelites (sedimentary rock, made of fine particles)...
                              >>> ancient river beds, lake shores, estuaries? ---m3d

                              >> Thanks, yes, but I'd like to see more specific correlations.
                              >> Sahelanthr in Anthracotheriid Unit.
                              >> Remakable this association of hominid fossils with
                              >> hippopotamid ones. --Marc

                              > You may find this 2002 article(in Nature) of some
                              > interest ... as it gives some idea of the location
                              > in Chad where Toumai was found(including fauna and
                              > flora), it also includes a map giving an idea of
                              > the previous extent(sizes) of Lake Chad.
                              > It all seems to indicate that Toumai an its
                              > kin 7 Ma, lived close to Lake (inland sea?)
                              > Chad, if not on the lake shore.
                              > Abstract:
                              > All six known specimens of the early hominid
                              > Sahelanthropus tchadensis come from Toros-Menalla
                              > site 266 (TM 266), a single locality in the
                              > Djurab Desert, northern Chad, central Africa.
                              > Here we present a preliminary analysis of the
                              > palaeontological and palaeoecological context
                              > of these finds. The rich fauna from TM 266
                              > includes a significant aquatic component such
                              > as fish, crocodiles and amphibious mammals,
                              > alongside animals associated with gallery forest
                              > and savannah, such as primates, rodents, elephants,
                              > equids and bovids. The fauna suggests a
                              > biochronological age between 6 and 7 million years.
                              > Taken together with the sedimentological evidence,
                              > the fauna suggests that S.tchadensis lived close
                              > to a lake, but not far from a sandy desert, perhaps
                              > the oldest record of desert conditions in the
                              > Neogene of northern central Africa.
                              > Geology and palaeontology of the Upper Miocene
                              > Toros-Menalla hominid locality, Chad
                              > http://tinyurl.com/2vkwlt ---m3d

                              Thanks a lot, m3d, yes, possibly an inland sea: AFAIK the anthracotheres
                              came from the shallow seas in the Lybian Sirt basin (F.Lihoreau cs.2006 PNAS
                              6:8763-7). I'm trying to imagine how this milieu looked like, I guess flat
                              + water, trees & grass?

                              --Marc
                            • m3dodds
                              ... The Eosahabi river once flowed north from Lake Chad through Libya, to reach the Mediterranean sea ... Aren t the anthracothere, supposed to have been the
                              Message 14 of 15 , Mar 3, 2008
                              • 0 Attachment
                                --- In AAT@yahoogroups.com, Marc Verhaegen <marc.verhaegen@...> wrote:
                                >
                                > Op 02-03-2008 18:24, m3dodds <dons3148@...> schreef:
                                >
                                > >>>>> http://www.pnas.org/cgi/content/abstract/0708015105v1
                                >
                                > >>>> Fig.1+2: Both fossil seem to lay in argillaceous pelites?
                                > >>>> Abel ass.x fish cf.fig.2?
                                > >>>> What does "argillaceous pelites" imply? --Marc
                                >
                                > >>> argillaceous ... (containing clay, or clay like) and
                                > >>> pelites (sedimentary rock, made of fine particles)...
                                > >>> ancient river beds, lake shores, estuaries? ---m3d
                                >
                                > >> Thanks, yes, but I'd like to see more specific correlations.
                                > >> Sahelanthr in Anthracotheriid Unit.
                                > >> Remakable this association of hominid fossils with
                                > >> hippopotamid ones. --Marc
                                >
                                > > You may find this 2002 article(in Nature) of some
                                > > interest ... as it gives some idea of the location
                                > > in Chad where Toumai was found(including fauna and
                                > > flora), it also includes a map giving an idea of
                                > > the previous extent(sizes) of Lake Chad.
                                > > It all seems to indicate that Toumai an its
                                > > kin 7 Ma, lived close to Lake (inland sea?)
                                > > Chad, if not on the lake shore.
                                > > Abstract:
                                > > All six known specimens of the early hominid
                                > > Sahelanthropus tchadensis come from Toros-Menalla
                                > > site 266 (TM 266), a single locality in the
                                > > Djurab Desert, northern Chad, central Africa.
                                > > Here we present a preliminary analysis of the
                                > > palaeontological and palaeoecological context
                                > > of these finds. The rich fauna from TM 266
                                > > includes a significant aquatic component such
                                > > as fish, crocodiles and amphibious mammals,
                                > > alongside animals associated with gallery forest
                                > > and savannah, such as primates, rodents, elephants,
                                > > equids and bovids. The fauna suggests a
                                > > biochronological age between 6 and 7 million years.
                                > > Taken together with the sedimentological evidence,
                                > > the fauna suggests that S.tchadensis lived close
                                > > to a lake, but not far from a sandy desert, perhaps
                                > > the oldest record of desert conditions in the
                                > > Neogene of northern central Africa.
                                > > Geology and palaeontology of the Upper Miocene
                                > > Toros-Menalla hominid locality, Chad
                                > > http://tinyurl.com/2vkwlt ---m3d
                                >
                                > Thanks a lot, m3d, yes, possibly an inland sea:
                                > AFAIK the anthracotheres came from the shallow
                                > seas in the Lybian Sirt basin (F.Lihoreau cs.2006
                                > PNAS 6:8763-7).


                                The Eosahabi river once flowed north from Lake
                                Chad through Libya, to reach the Mediterranean
                                sea ...

                                Aren't the anthracothere, supposed to have been
                                the missing link between whales and hippos?




                                > I'm trying to imagine how this milieu looked
                                > like, I guess flat + water, trees & grass?
                                >
                                > --Marc


                                Doubt it was flat, but you could be right about
                                water, trees and grass ... as the changeable
                                climate of the period is said to have favoured
                                more adaptable species. Species that favoured
                                littoral, riparian and woodland habitats.

                                More on Lake Chad:
                                See the maps at the bottom of the page, indicating
                                the rapid change(shrinkage) in the size of Lake
                                Chad in the last fifty years.

                                http://www.solcomhouse.com/africalchad.htm


                                ---m3d
                              • Marc Verhaegen
                                ... Ok. ... Possible: AFAIK they re fossil relatives of hippos. ... Thanks a lot, m3d, very interesting & very sad... --Marc
                                Message 15 of 15 , Mar 3, 2008
                                • 0 Attachment
                                  Op 03-03-2008 13:19, m3dodds <dons3148@...> schreef:


                                  >>>>>>> http://www.pnas.org/cgi/content/abstract/0708015105v1

                                  >>>>>> Fig.1+2: Both fossil seem to lay in argillaceous pelites?
                                  >>>>>> Abel ass.x fish cf.fig.2?
                                  >>>>>> What does "argillaceous pelites" imply? --Marc

                                  >>>>> argillaceous ... (containing clay, or clay like) and
                                  >>>>> pelites (sedimentary rock, made of fine particles)...
                                  >>>>> ancient river beds, lake shores, estuaries? ---m3d

                                  >>>> Thanks, yes, but I'd like to see more specific correlations.
                                  >>>> Sahelanthr in Anthracotheriid Unit.
                                  >>>> Remakable this association of hominid fossils with
                                  >>>> hippopotamid ones. --Marc

                                  >>> You may find this 2002 article(in Nature) of some
                                  >>> interest ... as it gives some idea of the location
                                  >>> in Chad where Toumai was found(including fauna and
                                  >>> flora), it also includes a map giving an idea of
                                  >>> the previous extent(sizes) of Lake Chad.
                                  >>> It all seems to indicate that Toumai an its
                                  >>> kin 7 Ma, lived close to Lake (inland sea?)
                                  >>> Chad, if not on the lake shore.
                                  >>> Abstract:
                                  >>> All six known specimens of the early hominid
                                  >>> Sahelanthropus tchadensis come from Toros-Menalla
                                  >>> site 266 (TM 266), a single locality in the
                                  >>> Djurab Desert, northern Chad, central Africa.
                                  >>> Here we present a preliminary analysis of the
                                  >>> palaeontological and palaeoecological context
                                  >>> of these finds. The rich fauna from TM 266
                                  >>> includes a significant aquatic component such
                                  >>> as fish, crocodiles and amphibious mammals,
                                  >>> alongside animals associated with gallery forest
                                  >>> and savannah, such as primates, rodents, elephants,
                                  >>> equids and bovids. The fauna suggests a
                                  >>> biochronological age between 6 and 7 million years.
                                  >>> Taken together with the sedimentological evidence,
                                  >>> the fauna suggests that S.tchadensis lived close
                                  >>> to a lake, but not far from a sandy desert, perhaps
                                  >>> the oldest record of desert conditions in the
                                  >>> Neogene of northern central Africa.
                                  >>> Geology and palaeontology of the Upper Miocene
                                  >>> Toros-Menalla hominid locality, Chad
                                  >>> http://tinyurl.com/2vkwlt ---m3d

                                  >> Thanks a lot, m3d, yes, possibly an inland sea:
                                  >> AFAIK the anthracotheres came from the shallow
                                  >> seas in the Lybian Sirt basin (F.Lihoreau cs.2006
                                  >> PNAS 6:8763-7).

                                  > The Eosahabi river once flowed north from Lake
                                  > Chad through Libya, to reach the Mediterranean
                                  > sea ...

                                  Ok.

                                  > Aren't the anthracothere, supposed to have been
                                  > the missing link between whales and hippos?

                                  Possible: AFAIK they're fossil relatives of hippos.

                                  >> I'm trying to imagine how this milieu looked
                                  >> like, I guess flat + water, trees & grass? --Marc

                                  > Doubt it was flat, but you could be right about
                                  > water, trees and grass ... as the changeable
                                  > climate of the period is said to have favoured
                                  > more adaptable species. Species that favoured
                                  > littoral, riparian and woodland habitats.
                                  > More on Lake Chad:
                                  > See the maps at the bottom of the page, indicating
                                  > the rapid change (shrinkage) in the size of Lake
                                  > Chad in the last fifty years.
                                  > http://www.solcomhouse.com/africalchad.htm
                                  > ---m3d

                                  Thanks a lot, m3d, very interesting & very sad...

                                  --Marc
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